surnamed the Macedonian, emperor of the Greeks. He was a common folder, and of an obscure family in Macedonia, and yet raised himself to the throne; for having pleased the emperor Michael by his address in the management of his horses, he became his first equerry, and then his great chamberlain. He at length affianced the famous Bardas, and was associated to the empire in 849. He held the eighth general council at Constantinople; deposed the patriarch Photius, but in 858 restored him to the patriarchate; and declared against the popes, who refused to admit him into their communion. He was dreaded by his enemies the Saracens, whom he frequently vanquished; and loved by his subjects, for his justice and clemency. He died in 886. Under his reign the Ruffians embraced Christianity, and the doctrine of the Greek church. He ought not to be confounded with Basilus the Younger, who succeeded Zemistus in 975, and after a reign of 50 years died in 1025.